Oversized via as through-substrate-via (tsv) stop layer

ABSTRACT

The present disclosure, in some embodiments, relates to an integrated chip structure. The integrated chip structure includes a first via disposed within a dielectric structure on a substrate, and a second via disposed within the dielectric structure and laterally separated from the first via by the dielectric structure. The first via has a first width that is smaller than a second width of the second via. An interconnect wire vertically contacts the second via and extends laterally past an outermost sidewall of the second via. A through-substrate via (TSV) is arranged over the second via and extends through the substrate. The TSV has a minimum width that is smaller than the second width of the second via. The second via has opposing outermost sidewalls that are laterally outside of the TSV.

REFERENCE TO RELATED APPLICATIONS

This Application is a Continuation of U.S. application Ser. No.17/696,357, filed on Mar. 16, 2022, which is a Continuation of U.S.application No. 16/898,647, filed on Jun. 11, 2020 (now U.S. Pat. No.11,282,769, issued on Mar. 22, 2022). The contents of theabove-referenced Patent Applications are hereby incorporated byreference in their entirety.

BACKGROUND

Integrated chip fabrication is a complex multiple-step process duringwhich electronic circuits are formed on a wafer made out of asemiconducting material (e.g., silicon). Integrated chip fabrication canbe broadly divided into front-end-of-line (FEOL) processing andback-end-of-line (BEOL) processing. FEOL processing generally relates tothe formation of devices (e.g., transistors) within the semiconductormaterial, while BEOL processing generally relates to the formation ofconductive interconnect layers within a dielectric structure over thesemiconductor material. After BEOL processing is completed, bond padsare formed and then the wafer may be singulated (e.g., diced) to form aplurality of separate integrated chip die.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the present disclosure are best understood from the followingdetailed description when read with the accompanying figures. It isnoted that, in accordance with the standard practice in the industry,various features are not drawn to scale. In fact, the dimensions of thevarious features may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 illustrates a cross-sectional view of some embodiments of anintegrated chip structure having an oversized via configured to act as astop layer for a through-substrate via (TSV).

FIG. 2 illustrates a cross-sectional view of some embodiments of amulti-dimensional integrated chip structure having an oversized via.

FIGS. 3-10 illustrate some additional embodiments of an integrated chipstructure having an oversized via.

FIGS. 11-21 illustrate cross-sectional views of some embodiments of amethod of forming an integrated chip structure having an oversized via.

FIG. 22 illustrates a flow diagram of some embodiments of a method offorming an integrated chip structure having an oversized via.

FIGS. 23-33 illustrate cross-sectional views of some alternativeembodiments of a method of forming an integrated chip structure havingan oversized via.

FIG. 34 illustrates a flow diagram of some alternative embodiments of amethod of forming an integrated chip structure having an oversized via.

DETAILED DESCRIPTION

The following disclosure provides many different embodiments, orexamples, for implementing different features of the provided subjectmatter. Specific examples of components and arrangements are describedbelow to simplify the present disclosure. These are, of course, merelyexamples and are not intended to be limiting. For example, the formationof a first feature over or on a second feature in the description thatfollows may include embodiments in which the first and second featuresare formed in direct contact, and may also include embodiments in whichadditional features may be formed between the first and second features,such that the first and second features may not be in direct contact. Inaddition, the present disclosure may repeat reference numerals and/orletters in the various examples. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various embodiments and/or configurations discussed.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The apparatus may be otherwise oriented (rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly.

Three-dimensional integrated chips (3DIC) comprise a plurality ofintegrated chip (IC) tiers stacked onto one another. The plurality of ICtiers respectively comprise a semiconductor substrate. One or more ofthe plurality of IC tiers may also comprise a plurality of interconnectlayers disposed within a dielectric structure on a front-side of asemiconductor substrate. The plurality of interconnect layers compriseconductive interconnect wires and vias, which increase in size from athin interconnect layer (e.g., a “metal 1” layer) to a thickerinterconnect layer (e.g., a “top metal” layer) as a distance from thesemiconductor substrate increases. In some 3DIC, the plurality ofinterconnect layers may be coupled to a bond pad structure located alonga back-side of the semiconductor substrate. In such 3DIC, athrough-substrate via (TSV) extends through the semiconductor substrateto connect the plurality of interconnect layers to the bond padstructure.

A TSV may be formed by etching the back-side of the semiconductorsubstrate to form a TSV opening that extends through the semiconductorsubstrate to one of the plurality of interconnect layers. A conductivematerial is subsequently formed within the TSV opening. To minimizedisruption of routing of the plurality of interconnect layers, the TSVopening may be formed to extend to a thin interconnect layer (e.g., a“metal 1” layer). However, it has been appreciated that an etchingprocess used to form the TSV opening may damage the thin interconnectlayer. For example, when an etchant used to form the TSV opening reachesthe thin interconnect layer, the etchant may vertically over-etchthrough the thin interconnect layer. Over-etching through the thininterconnect layer can lead to reliability problems (e.g., timedependent dielectric breakdown (TDDB), leakage, and/or chip failure).

The present disclosure, in some embodiments, relates to an integratedchip structure comprising an oversized via that is configured to act asa stop layer for a through-substrate via (TSV). The integrated chipstructure may comprise a plurality of interconnects disposed within adielectric structure on a substrate. The plurality of interconnectscomprise a first interconnect wire layer and a first via layer. Thefirst interconnect wire layer comprises a first interconnect wire and asecond interconnect wire. The first via layer comprises a standard viaphysically contacting the first interconnect wire and an oversized viaphysically contacting the second interconnect wire. The oversized via islarger (e.g., wider) than the standard via. A TSV extends through thesubstrate to physically contact the second interconnect wire and/or theoversized via. The oversized via laterally extends past opposing sidesof the TSV, so that the second interconnect wire and oversized via areable to form a thick interconnect structure that can effectively act asa stop layer for an etching process used to form the TSV. By using theoversized via to act as part of a stop layer for an etching process usedto form the TSV, negative effects (e.g., time dependent dielectricbreakdown, leakage, and/or chip failure) of over-etching through thesecond interconnect wire can be mitigated.

FIG. 1 illustrates a cross-sectional view of some embodiments of anintegrated chip structure 100 having an oversized via configured to actas a stop layer for a through-substrate via (TSV).

The integrated chip structure 100 comprises a plurality of interconnectlayers 106 disposed within a dielectric structure 104 on a first side103 a (e.g., a front-side) of a substrate 102. The plurality ofinterconnect layers 106 comprise a plurality of interconnect wire layers108 a-108 b vertically separated from one another by a plurality of vialayers 110 a-110 b. The plurality of interconnect wire layers 108 a-108b are configured to provide for lateral routing, while the plurality ofvia layers 110 a-110 b are configured to provide for vertical routingbetween adjacent ones of the plurality of interconnect wire layers 108a-108 b. The plurality of interconnect wire layers 108 a-108 b and theplurality of via layers 110 a-110 b may have sizes (e.g., heights and/orwidths) that increase as a distance from the substrate 102 increases.For example, in some embodiments, the plurality of interconnect wirelayers 108 a-108 b may comprise a first interconnect wire layer 108 aand a second interconnect wire layer 108 b separated from the substrate102 by the first interconnect wire layer 108 a. The first interconnectwire layer 108 a has interconnect wires with a first size (e.g., a firstheight and/or width) and the second interconnect layer 108 b hasinterconnect wires with a second size (e.g., a second height and/orwidth) that is larger than the first size.

In some embodiments, the first interconnect wire layer 108 a maycomprise a first interconnect wire 109 w ₁ and a second interconnectwire 109 w ₂. The first interconnect wire 109 w ₁ is laterally separatedfrom the second interconnect wire 109 w ₂ by way of the dielectricstructure 104. In some embodiments, the plurality of via layers 110a-110 b may comprise a first via layer 110 a having a standard via 111 v_(s) and an oversized via 111 v _(o). The oversized via 111 v _(o) has alarger size (e.g., width) than the standard via 111 v _(s). In someembodiments, the standard via 111 v _(s) physically contacts the firstinterconnect wire 109 w ₁ and the oversized via 111 v _(o) physicallycontacts the second interconnect wire 109 w ₂. In some embodiments, theoversized via 111 v _(o) may also have a larger size (e.g., width) thana via on a second via layer 110 b.

A through-substrate via (TSV) 112 extends through the substrate 102 tocontact the second interconnect wire 109 w ₂ and/or the oversized via111 v _(o). In some embodiments, the TSV 112 may further contact a bondpad structure 114 that is disposed along a second side 103 b of thesubstrate 102 and that is surrounded by a passivation structure 116. Aconductive bonding structure 118 (e.g., a conductive bump, a conductivepost, and/or the like) is disposed on the bond pad structure 114.

The TSV 112 has a minimum width that is smaller than a width of theoversized via 111 v _(o). In some embodiments, the oversized via 111 v_(o) laterally extends past opposing sides of the TSV 112. Because theoversized via 111 v _(o) is wider than the TSV 112, the secondinterconnect wire 109 w ₂ and the oversized via 111 v _(o) are able tocollectively define a thick interconnect structure that can effectivelyact as a stop layer for an etch used to form the TSV 112. Having thesecond interconnect wire 109 w ₂ and the oversized via 111 v _(o)collectively act as a stop layer mitigates negative effects ofover-etching through a thin interconnect layer.

Furthermore, the oversized via 111 v _(o) is also able to provide theintegrated chip structure 100 with good electrical performance. Forexample, in some embodiments, the TSV 112 may be configured to carryrelatively large currents (e.g., greater than 10 mA, greater than 50 mA,or the like), which may result in a large current density withinstandard vias on thin interconnect layers. The large current density canlead to high resistances and/or increased electro-migration betweeninterconnect wires and vias, leading to performance and/or reliabilityproblems. To prevent large current densities within a standard via,large arrays of standard vias can be placed between thin interconnectwires coupled to the TSV 112 to distribute a large current. However,such via arrays consume a large footprint that can negatively impactinterconnect routing. The oversized via 111 v _(o) is able to carry alarge current at a relatively low current density (e.g., a currentdensity that is lower than the standard via) while consuming arelatively small footprint (e.g., a footprint smaller than a via arraythat would provide for a same current density), thereby providing for agood electrical performance (e.g., relatively low resistance and/orelectro-migration) without substantially compromising routing of theplurality of interconnect layers 106.

FIG. 2 illustrates a cross-sectional view of some embodiments of amulti-dimensional integrated chip structure 200 having an oversized via.

The multi-dimensional integrated chip structure 200 comprises aplurality of integrated chip (IC) tiers 202 a-202 b stacked onto oneanother. In some embodiments, the plurality of IC tiers 202 a-202 b mayrespectively comprise an IC die (singulated from wafers), a wafercomprising a plurality of IC die, or the like. In some embodiments, theplurality of IC tiers 202 a-202 b may comprise a first IC tier 202 a anda second IC tier 202 b. In some embodiments, the first IC tier 202 a maycomprise a first plurality of interconnect layers 106 a disposed withina first dielectric structure 104 a on a first substrate 102 a. In someembodiments, the second IC tier 202 b may comprise a second plurality ofinterconnect layers 106 b disposed within a second dielectric structure104 b on a second substrate 102 b. In various embodiments, the firstsubstrate 102 a and the second substrate 102 b may be any type ofsemiconductor body (e.g., silicon, SiGe, SOI, etc.), as well as anyother type of semiconductor, epitaxial, dielectric, or metal layers,associated therewith. In some embodiments, the first plurality ofinterconnect layers 106 a and the second plurality of interconnectlayers 106 b may comprise a metal such as copper, aluminum, tungsten, orthe like.

The first IC tier 202 a is coupled to the second IC tier 202 b by way ofa bonding structure 204. In some embodiments, the bonding structure 204may comprise a hybrid bonding structure having a bonding interface 203comprising metal bonding regions 206 and dielectric bonding regions 208.In some embodiments, one or more of the metal bonding regions 206 may becoupled to interconnects, within the first dielectric structure 104 aand the second dielectric structure 104 b, which are coupled to deviceswithin the first substrate 102 a and/or the second substrate 102 b. Insome additional embodiments, one or more of the metal bonding regions206 may be coupled between a first dummy interconnect 106 d ₁ within thefirst dielectric structure 104 a and a second dummy interconnect 106 d ₂within the second dielectric structure 104 b. The first dummyinterconnect 106 d ₁ and the second dummy interconnect 106 d ₂ are notelectrically coupled to devices (e.g., transistor devices) within themulti-dimensional integrated chip structure 200. In other embodiments(not shown), the bonding structure 204 may comprise a dielectric bondingstructure having one or more dielectric materials extending along anentirety of the bonding interface 203.

The second plurality of interconnect layers 106 b comprise a firstinterconnect wire layer 108 a and a first via layer 110 a. The firstinterconnect wire layer 108 a is vertically between the second substrate102 b and the first via layer 110 a. The first interconnect wire layer108 a has a first interconnect wire 109 w ₁ and a second interconnectwire 109 w ₂. The first via layer 110 a has a standard via 111 v_(s)physically contacting the first interconnect wire 109 w ₁ and anoversized via 111 v _(o) physically contacting the second interconnectwire 109 w ₂. The oversized via 111 v _(o) has a larger width than thestandard via 111 v _(s). In some embodiments the standard via 111 v _(s)and the oversized via 111 v _(o) may be a same material (e.g., copper,aluminum, tungsten, or the like).

A TSV 112 extends through the second substrate 102 b to contact thesecond interconnect wire 109 w ₂. In some embodiments, the TSV 112 mayextend into the second interconnect wire 109 _(w2) so that sidewalls ofthe second interconnect wire 109 _(w2) laterally surround a part of theTSV 112. In some additional embodiments, the TSV 112 may extend throughthe second interconnect wire 109 _(w2) to further contact the oversizedvia 111 v _(o). In some embodiments, the TSV 112 further contacts a bondpad structure 114 disposed along a back-side of the second substrate 102b and surrounded by a passivation structure 116. In some embodiments,the bond pad structure 114 comprises one or more redistribution layers(RDL). For example, in some embodiments the bond pad structure 114 maycomprise an RDL via 210 and an RDL wire 212.

In some embodiments, the passivation structure 116 may comprise one ormore lower passivation layers 214-216 below the bond pad structure 114and one or more upper passivation layers 218-220 over the bond padstructure 114. In some embodiments, the one or more lower passivationlayers 214-216 may comprise a first lower passivation layer 214 disposedon the second substrate 102 b and a second lower passivation layer 216disposed on the first lower passivation layer 214. In some embodiments,the one or more upper passivation layers 218-220 may comprise a firstupper passivation layer 218 disposed on the second lower passivationlayer 216 and a second upper passivation layer 220 disposed on the firstupper passivation layer 218. In some embodiments, the first lowerpassivation layer 214 and the second upper passivation layer 220 maycomprise a nitride (e.g., silicon nitride), a carbide (e.g., siliconcarbide), or the like. In some embodiments, the second lower passivationlayer 216 and the first upper passivation layer 218 may comprisesilicate glass (USG), borophosphosilicate glass (BPSG), or the like.

The one or more upper passivation layers 218-220 have sidewalls thatdefine an opening directly over the bond pad structure 114. A conductivebonding structure 118 is disposed within the opening and on the bond padstructure 114. In some embodiments, the conductive bonding structure 118may comprise an under bump metallurgy (UBM) 118 a disposed onto the bondpad structure 114 and a conductive bump 118 b (e.g., a solder bump)disposed onto the UBM 118 a. The UBM 118 a includes a diffusion barrierlayer and a seed layer. The diffusion barrier layer may also function asan adhesion layer (or a glue layer), in some embodiments. The diffusionbarrier layer may comprise tantalum, tantalum nitride, titanium,titanium nitride, or combination thereof. The seed layer comprises amaterial that is configured to enable deposition of metal posts, solderbumps, or the like. In other embodiments (not shown), the conductivebonding structure 118 may comprise a UBM 118 a disposed onto the bondpad structure 114 and a conductive post (e.g., a copper post, a coppermicro-post, or the like) disposed on the UBM 118 a.

FIG. 3 illustrates a cross-sectional view of some alternativeembodiments of an integrated chip 300 having an oversized via configuredto act as a stop layer for a TSV.

The integrated chip 300 comprises a first IC tier 202 a and a second ICtier 202 b. The first IC tier 202 a is coupled to the second IC tier 202b by way of a bonding structure 204. The second IC tier 202 b comprisesa second plurality of interconnect layers 106 b disposed on a secondsubstrate 102 b. The second plurality of interconnect layers 106 bincludes a first interconnect wire layer 108 a and a first via layer 110a. The first via layer 110 a is vertically between a second substrate102 b and the first interconnect wire layer 108 a. The firstinterconnect wire layer 108 a has a first interconnect wire 109 w ₁ anda second interconnect wire 109 w ₂. The first via layer 110 a has astandard via 111 v _(s) contacting the first interconnect wire 109 w ₁and an oversized via 111 v _(o) contacting the second interconnect wire109 w ₂.

In some embodiments, the standard via 111 v _(s) and the oversized via111 v _(o) may contact the second substrate 102 b. In some suchembodiments, the standard via 111 v _(s) and the oversized via 111 v_(o) may comprise a different material than the first interconnect wire109 w ₁ and a second interconnect wire 109 w ₂. For example, thestandard via 111 v _(s) and the oversized via 111 v _(o) may comprisetungsten, while the first interconnect wire 109 w ₁ and a secondinterconnect wire 109 w ₂ may comprise copper. In other embodiments (notshown), the standard via 111 v _(s) and the oversized via 111 v _(o) maybe separated from the second substrate 102 b by one or more layers(e.g., one or more middle-end-of-the-line (MEOL) layers). In some suchembodiments, the standard via 111 v _(s) and the oversized via 111 v_(o) may comprise a same material (e.g., copper) as the firstinterconnect wire 109 w ₁ and a second interconnect wire 109 w ₂.

A TSV 112 extends through the second substrate 102 b to contact theoversized via 111 v _(o). In some embodiments, the TSV 112 may extendinto the oversized via 111 v _(o) so that sidewalls of the oversized via111 v _(o) laterally surround a part of the TSV 112. In some additionalembodiments, the TSV 112 may extend through the oversized via 111 v _(o)to further contact the second interconnect wire 109 w ₂.

In some embodiments, a via array 302 comprising a plurality of vias maycontact a side of the second interconnect wire opposing the oversizedvia 111 v _(o). The via array 302 is able to carry a relatively largecurrent without causing a high current density within individual vias ofthe via array 302 that may be detrimental to reliability or cause a highresistance. In some embodiments, the via array 302 may have a width thatis greater than or equal to the oversized via 111 v _(o). In someembodiments, the oversized via 111 v _(o) may reduce a resistancemeasured between the TSV 112 and the second interconnect wire 109 w ₂ byup to approximately 25% compared TSV landing directly onto the secondinterconnect wire 109 w ₂. In other embodiments (not shown), a secondoversized via may contact the side of the second interconnect wire 109 w₂ opposing the oversized via 111 v _(o).

FIGS. 4A-4B illustrate some additional embodiments of an integrated chipstructure having an oversized via configured to act as a stop layer fora TSV.

As shown in cross-sectional view 400 of FIG. 4A, the integrated chipstructure comprises a dielectric structure 104 arranged on a first side(e.g., a front-side) of a substrate 102. In some embodiments, atransistor device 402 is disposed within the substrate 102. Thetransistor device 402 comprises a gate structure 404 disposed between asource region 406 a and a drain region 406 b. In some embodiments, thegate structure 404 may comprise a polysilicon gate electrode separatedfrom the substrate 102 by way of a dielectric material (e.g., silicondioxide, silicon nitride, or the like). In some embodiments, sidewallspacers 408 may be disposed along opposing sides of the gate structure404. In some embodiments, isolation structures 410 may be disposedwithin the substrate 102 on opposing sides of the transistor device 402.In some embodiments, the isolation structures 410 may comprise shallowtrench isolation (STI) structures.

The dielectric structure 104 comprises a plurality of inter-leveldielectric (ILD) layers 414 a-414 b stacked onto one another. In someembodiments, one or more of the plurality of ILD layers 414 a-414 b maycomprise an ultra low-k (ULK) dielectric material or an extreme low-k(ELK) dielectric material. The ULK and ELK dielectric materials have alower mechanical strength (e.g., are more porous) than low-k dielectricmaterials within the dielectric structure 104. In some embodiments, thedielectric structure 104 may be separated from the substrate 102 by wayof a contact etch stop layer (CESL) 412. In some embodiments, the CESL412 extends to over an upper surface of the gate structure 404. In someembodiments, the plurality of ILD layers 414 a-414 b may be separatedfrom one another by etch stop layers 416 a-416 b.

A standard via 111 v _(s) and an oversized via 111 v _(o) are disposedwithin a first ILD layer 414 a. A first interconnect wire 109 w ₁ and asecond interconnect wire 109 w ₂ are disposed within a second ILD layer414 b on the first ILD layer 414 a. The standard via 111 v _(s) contactsthe first interconnect wire 109 w ₁ and the oversized via 111 v _(o)contacts the second interconnect wire 109 w ₂. The oversized via 111 v_(o) has a larger size than the standard via 111 v _(s).

A TSV 112 extends through the substrate 102 and between the oversizedvia 111 v _(o) and a bond pad structure 114 disposed along a back-sideof the substrate 102. In some embodiments, the TSV 112 may comprise aback-side through-substrate via (BTSV). In such embodiments, the TSV 112may have tapered sidewalls so that the TSV 112 has a greater width alonga second side (e.g., a back-side) of the substrate 102 than along thefirst side of the substrate 102. In some embodiments, the TSV 112 mayhave a top surface that has a width 418. In some embodiments, the width418 may be between approximately 500 μm and approximately 900 μm,between approximately 600 μm and approximately 800 μm, approximatelyequal to approximately 700 μm, or other similar values.

The TSV 112 contacts the oversized via 111 v _(o) along an interfacethat is separated from the dielectric structure 104 by the oversized via111 v _(o). It has been appreciated that when the TSV 112 contacts theoversized via 111 v _(o) along an interface comprising a ULK or ELKmaterial, that an etchant used to form the TSV 112 may laterallyover-etch the ULK or ELK material, leading to reliability concerns(e.g., TDDB). However, by separating the TSV 112 from the dielectricstructure 104, damage (e.g., lateral over-etching) to ULK and/or ELKmaterials within the dielectric structure 104 can be mitigated andreliability of the integrated chip structure can be improved. In someembodiments, the TSV 112 may extend through one or more of the isolationstructures 410. In such embodiments, when an etchant is used to etchthrough the substrate 102, the etchant will contact the oversized via111 v _(o) at a position that is laterally surrounded by the isolationstructure 410.

As shown in top-view 420 of FIG. 4B, the oversized via 111 v _(o) andthe second interconnect wire 109 w ₂ laterally extend past opposingsidewalls of the TSV 112. In some embodiments, the second interconnectwire 109 w ₂ may also laterally extend past opposing sidewalls of theoversized via 111 v _(o). In some embodiments, the oversized via 111 v_(o) continuously extends without openings between outermost sidewallsof the oversized via 111 v _(o) along a first direction and along asecond direction that is perpendicular to the first direction.

In some embodiments, the oversized via 111 v _(o) may have a length 422and a width 424 in a range of between approximately 0.5 μm andapproximately 2 μm, between approximately 0.8 μm and approximately 1.0μm, or other similar values. In some embodiments, the oversized via 111v _(o) may extend past an edge of the TSV 112 for a distance 426 that isin a range of between approximately 0 μm and approximately 100 μm,between approximately 60 μm and approximately 90 μm, or similar values.

In some embodiments, the length 422 and the width 424 of the oversizedvia 111 v _(o) may be between approximately 400% and approximately5,000% larger than a length 428 and a width 430 of the standard via 111v _(s). In other embodiments, the length 422 and the width 424 of theoversized via 111 v _(o) may be between approximately 2,000% andapproximately 5,000% larger than the length 428 and the width 430 of thestandard via 111 v _(s). In some embodiments, the length 428 and thewidth 430 of the standard via 111 v _(s) may be in a range of betweenapproximately 0.01 micron (μm) and approximately 0.5 μm, betweenapproximately 0.01 μm and approximately 0.05 μm, or other similarvalues.

The relatively large size of the oversized via 111 v _(o) providesimproved electrical and design characteristics compared to the standardvia 111 v _(s) or an array of standard vias. For example, the oversizedvia 111 v _(o) is able carry a same current as an array of standard viaswhile consuming a smaller area (e.g., an array of 16 standard viashaving a collective length and width of approximately 3.22 μm may beable to collectively carry a current of approximately 48 mA, while anoversized via 111 v _(o) having a length and width of approximately 1.6μm may be able to carry a current of approximately 48 mA at a samecurrent density). In some embodiments, the oversized via 111 v _(o) cancarry a same current as an array of standard vias, while consuming anarea that is approximately equal to 25% of the array. Alternatively, theoversized via 111 v _(o) may carry a larger current than an array ofstandard vias having a same area (e.g., an array of 16 standard viashaving a collective length and width of approximately 3.22 μm may beable to collectively carry a current of approximately 48 mA, while anoversized via 111 v _(o) having a length and width of approximately 3.22μm may be able to carry a current of 190 mA at a same current density).In some embodiments, the oversized via 111 v _(o) may carry a currentthat is over 4 times larger than that of an array of standard vias at asame current density.

FIG. 5 illustrates a cross-sectional view of some additional embodimentsof an integrated chip structure 500 having an oversized via configuredto act as a stop layer for a TSV.

The integrated chip structure 500 comprises a transistor device 502disposed along a front-side of the substrate 102. The transistor device502 comprises a gate structure 504 disposed between a source region 406a and a drain region 406 b. The gate structure 504 may comprise a metalgate electrode that is separated from the substrate 102 by a high-Kdielectric material. In some embodiments, the metal gate electrode maycomprise aluminum, tungsten, or the like. In some embodiments, thehigh-κ dielectric material may comprise hafnium oxide, aluminum oxide,or the like. In some embodiments, sidewall spacers 506 may be disposedalong opposing sides of the gate structure 504.

A contact etch stop layer (CESL) 508 is disposed over the substrate 102and along sidewalls of the gate structure 504. The CESL 508 does notextend over a top of the gate structure 504. The gate structure 504 islaterally surrounded by a first ILD layer 414 a. A first etch stop layer416 a is disposed on the first ILD layer 414 a and a second ILD layer414 b is disposed on the first etch stop layer 416 a. A third ILD layer414 c is separated from the second ILD layer 414 b by way of a secondetch stop layer 416 b. A standard via 111 v _(s) and an oversized via111 v _(o) are disposed within the third ILD layer 414 c. The standardvia 111 v _(s) has a smaller size than the oversized via 111 v _(o). Insome embodiments, the oversized via 111 v _(o) may have a thickness 514that is in a range of between approximately 400 Angstroms (Å) andapproximately 700 Å, between approximately 500 Å and approximately 600Å, approximately 550 Å, or other similar values. In some embodiments,one or more middle-end-of-the-line (MEOL) interconnects 510-512 aredisposed vertically between the oversized via 111 v _(o) and thesubstrate 102.

A first interconnect wire 109 w ₁ and a second interconnect wire 109 w ₂are also disposed within the third ILD layer 414 c. The firstinterconnect wire 109 w ₁ contacts the standard via 111 v _(s) and thesecond interconnect wire 109 w ₂ contacts the oversized via 111 v _(o).In some embodiments, the second interconnect wire 109 w ₂ may have athickness 516 that is in a range of between approximately 500 Å andapproximately 800 Å, between approximately 600 Å and approximately 700Å, approximately 650 Å, or other similar values.

A TSV 112 extends through the substrate 102, the CESL 508, the first ILDlayer 414 a, the first etch stop layer 416 a, and the second ILD layer414 b. Because the TSV 112 extends through the first ILD layer 414 a andthe second ILD layer 414 b, the TSV 112 extends vertically past the oneor more MEOL interconnects 510-512. In some embodiments, the oversizedvia 111 v _(o) and the second interconnect wire 109 w ₂ may collectivelyhave a thickness that is greater than or equal to approximately 1,000 Å,approximately 1,200 Å, approximately 1,500 Å, or similar values. Suchcollective thicknesses provide for sufficient resistance to over-etchingto prevent an etchant used to form the TSV 112 from etching through theoversized via 111 v _(o) and the second interconnect wire 109 w ₂.

In various embodiments, the second ILD layer 414 b may have a firstmechanical strength and the third ILD layer 414 c may have a secondmechanical strength that is less than the first mechanical strength(e.g., the third ILD layer 414 c may be more porous than the second ILDlayer 414 b). For example, in some embodiments, the second ILD layer 414b may comprise a low-k dielectric material (e.g., a dielectric having adielectric constant around 3.0, such as undoped silicate glass (USG),fluorosilicate glass, organosilicate glass, or the like) and the thirdILD layer 414 c may comprise a ULK material or an ELK material (e.g., adielectric having a dielectric constant of around 2.5 or less, such asSiCOH, pSiCOH, or the like).

The TSV 112 contacts the oversized via 111 v _(o) along an interfacethat is separated from the third ILD layer 414 c. Because the TSV 112contacts the oversized via 111 v _(o) along an interface that isseparated from the third ILD layer 414 c, the oversized via 111 v _(o)prevents an etchant used to form the TSV 112 from contacting the thirdILD layer 414 c. Rather, the etchant used to form the TSV 112 contactsthe second ILD layer 414 b, which has a greater mechanical strength thanthe third ILD layer 414 c. The greater mechanical strength provides fora greater resistance to over-etching along a lateral direction. Bymitigating over-etching along a lateral direction, damage to thedielectric structure 104 is mitigated and reliability is improved.

FIG. 6 illustrates a cross-sectional view of some additional embodimentsof an integrated chip structure 600 having an oversized via configuredto act as a stop layer for a TSV.

The integrated chip structure 600 comprises a first IC tier 202 a and asecond IC tier 202 b. The first IC tier 202 a comprises a firstdielectric structure 104 a disposed on a first substrate 102 a andsurrounding a first plurality of interconnect layers 106 a. The secondIC tier 202 b comprises a second dielectric structure 104 b disposed ona second substrate 102 b and surrounding a second plurality ofinterconnect layers 106 b. In some embodiments, a sensor element notshown) may be disposed within the second substrate 102 b. The sensorelement is configured to generate an electrical signal in response toincident radiation (e.g., light). In some embodiments, the sensorelement includes a photodetector, such as a photodiode.

The first IC tier 202 a is bonded to the second IC tier 202 b in aface-to-back bonding configuration. In the face-to-back bondingconfiguration, the first substrate 102 a is vertically between the firstdielectric structure 104 a and the second dielectric structure 104 b. Insome embodiments, the first IC tier 202 a is bonded to the second ICtier 202 b by way of a bonding structure 601 disposed between aback-side of the first substrate 102 a and the second dielectricstructure 104 b. In some embodiments, the bonding structure 601comprises a first dielectric bonding layer 604 a disposed along theback-side of the first substrate 102 a and a second dielectric bondinglayer 604 b disposed along the second dielectric structure 104 b. Aplurality of conductive routing layers 602 a-602 b (e.g., RDL layers)and one or more conductive dummy bonding structures 606 are disposedwithin the first dielectric bonding layer 604 a. The first dielectricbonding layer 604 a is bonded to the second dielectric bonding layer 604b, the plurality of conductive routing layers 602 a-602 b are coupled toa top interconnect layer 108 t, and the plurality of conductive dummybonding structures 606 are bonded to dummy interconnects 108 d along ahybrid bonding interface.

A first TSV 112 a extends through the first substrate 102 a to couplethe first plurality of interconnect layers 106 a to the second pluralityof interconnect layers 106 b. The first TSV 112 a contacts a firstoversized via 111 v _(o1) disposed within the first dielectric structure104 a on the first substrate 102 a. In some embodiments, the first TSV112 a may extend through the first oversized via 111 v _(o1) to furthercontact a first interconnect wire 109 w ₁ within the first dielectricstructure 104 a.

A second TSV 112 b extends through the second substrate 102 b to couplethe second plurality of interconnect layers 106 b to a bond padstructure 114 disposed along a back-side of the second substrate 102 b.The second TSV 112 b contacts a second interconnect wire 109 w ₂disposed within the second dielectric structure 104 b on the secondsubstrate 102 b. In some embodiments, the second TSV 112 b may extendthrough the second interconnect wire 109 w ₂ to further contact a secondoversized via 111 v _(o2) within the second dielectric structure 104 b.

FIG. 7 illustrates a cross-sectional view of some additional embodimentsof an integrated chip structure 700 having an oversized via configuredto act as a stop layer for a TSV.

The integrated chip structure 700 comprises a first IC tier 202 a bondedto a second IC tier 202 b in a face-to-back bonding configuration. Afirst TSV 112 a extends through a first substrate 102 a to couple afirst plurality of interconnect layers 106 a within a first dielectricstructure 104 a to a second plurality of interconnect layers 106 bwithin a second dielectric structure 104 b. The first TSV 112 a contactsa first interconnect wire 109 w ₁ physically contacting a firstoversized via 111 v _(o1) within the first dielectric structure 104 a.

A second TSV 112 b extends through the second substrate 102 b to couplethe second plurality of interconnect layers 106 b to a bond padstructure 114 disposed along a back-side of the second substrate 102 b.The second TSV 112 b contacts a second interconnect wire 109 w ₂physically contacting a second oversized via 111 v _(o2) disposed withinthe second dielectric structure 104 b.

FIG. 8 illustrates a cross-sectional view of some additional embodimentsof an integrated chip structure 800 having an oversized via configuredto act as a stop layer for a TSV.

The integrated chip structure 800 comprises a dielectric structure 104disposed along a first side 103 a of a substrate 102 and surrounding aninterconnect wire layer 108 and a via layer 110. The interconnect wirelayer 108 comprises a first interconnect wire 109 w ₁ and a secondinterconnect wire 109 w ₂. The via layer 110 comprises a standard via111 v _(s) contacting the first interconnect wire 109 w ₁ and anoversized via 111 v _(o) contacting the second interconnect wire 109 w₂.

A TSV 112 that extends through a substrate 102 between the oversized via111 v _(o) and a bond pad structure 114 along a second side 103 b of thesubstrate 102 opposing the first side 103 a of the substrate 102. Insome embodiments, the TSV 112 has a first end 112 e ₁ that is proximateto the first side 103 a of the substrate 102 and a second end 112 e ₂that is proximate to the second side 103 b of the substrate 102. Thefirst end 112 e ₁ of the TSV 112 has a first width and the second end112 e ₂ of the TSV 112 has a second width that is larger than the firstwidth. In some embodiments, the first end 112 e ₁ of the TSV 112 has arounded surface that contacts the oversized via 111 v _(o) and/or thesecond interconnect wire 109 w ₂. In some embodiments, the TSV 112 mayextend through the oversized via 111 v _(o) to within the secondinterconnect wire 109 w ₂.

In some embodiments, the TSV 112 is laterally separated from thesubstrate 102 by a liner 802. In some embodiments, the liner 802 maycomprise a dielectric material such as an oxide (e.g., silicon dioxide),a nitride (e.g., silicon nitride), or the like.

FIG. 9 illustrates a cross-sectional view of some additional embodimentsof an integrated chip structure 900 having an oversized via configuredto act as a stop layer for a TSV.

The integrated chip structure 900 comprises a dielectric structure 104disposed along a first side of a substrate 102. The dielectric structure104 has a plurality of ILD layers 414 a-414 c separated by etch stoplayers 416 a-416 b. In some embodiments, a standard via 111 v _(s), anoversized via 111 v _(o), a first interconnect wire 109 w ₁, and asecond interconnect wire 109 w ₂ may be surrounded by a third ILD layer414 c. In some embodiments, the oversized via 111 v _(o) may extend fromwithin the third ILD layer 414 c, through a second etch stop layer 416b, and to within a second ILD layer 414 b. In such embodiments, theoversized via 111 v _(o) may extend a non-zero distance 902 past abottom of a standard via 111 v _(s) so that the oversized via 111 v _(o)has a surface that is disposed along a horizontal line that intersectsan underlying interconnect 904 (e.g., a MEOL interconnect). In some suchembodiments, a surface of the oversized via 111 v _(o) facing thesubstrate 102 does not contact an interconnect.

A TSV 112 extends through the substrate 102. In some embodiments, theTSV 112 may comprise a diffusion barrier layer 908 that separates ametal core 906 of the TSV 112 from a liner 802. In some embodiments, themetal core 906 may comprise copper, aluminum, or the like. In someembodiments, the diffusion barrier layer 908 may comprise tantalumnitride, titanium nitride, or the like.

In some embodiments, the liner 802 may extend outward from the substrate102 and through one or more of the plurality of ILD layers 414 a-414 band/or etch stop layers 416 a-416 b of the dielectric structure 104. Forexample, in some embodiments, the liner 802 may extend through a firstILD layer 414 a and a first etch stop layer 416 a to an end that iswithin a second ILD layer 414 b. In some embodiments, the liner 802 isseparated from the oversized via 111 v _(o) by way of dielectricstructure 104.

FIG. 10 illustrates a cross-sectional view of some additionalembodiments of an integrated chip structure 1000 having an oversized viaconfigured to act as a stop layer for a TSV.

The integrated chip structure 1000 comprises an oversized via 111 v _(o)laterally separated from a standard via 111 v _(s) by a dielectricstructure 104 on a substrate 102. The standard via 111 v _(s) isvertically between a first interconnect wire 109 w ₁ and a firstoverlying interconnect wire 1002 w ₁. The oversized via 111 v _(o) isvertically between a second interconnect wire 109 w ₂ and a secondoverlying interconnect wire 1002 w ₂. In some embodiments, the firstinterconnect wire 109 w ₁ and the second interconnect wire 109 w ₂ areseparated from the substrate 102 by one or more additional interconnectlayers (e.g., one or more MEOL interconnect layers). The standard via111 v _(s) and the oversized via 111 v _(o) have substantially similarheights. A TSV 112 vertically extends through the second interconnectwire 109 w ₂ and into the oversized via 111 v _(o) and/or the secondoverlying interconnect wire 1002 w ₂.

FIGS. 11-21 illustrate cross-sectional views 1100-2100 of someembodiments of a method of forming an integrated chip structure havingan oversized via configured to act as a stop layer for a TSV. AlthoughFIGS. 11-21 are described in relation to a method, it will beappreciated that the structures disclosed in FIGS. 11-21 are not limitedto such a method, but instead may stand alone as structures independentof the method.

As shown in cross-sectional view 1100 of FIG. 11 , a first integratedchip (IC) tier 202 a is formed. In some embodiments, the first IC tier202 a may be formed by forming a first plurality of interconnect layers106 a within a first dielectric structure 104 a formed over a firstsubstrate 102 a. In some embodiments, the first dielectric structure 104a may comprise a plurality of ILD layers stacked onto one another. Insome embodiments, the first plurality of interconnect layers 106 a maycomprise a conductive contact, an interconnect wire, and an interconnectvia. In some embodiments, the first plurality of interconnect layers 106a may be formed by damascene processes. In such embodiments, the firstplurality of interconnect layers 106 a may be formed by forming one ofthe plurality of ILD layers, selectively etching the ILD layer to definea via hole and/or a trench within the ILD layer, forming a conductivematerial (e.g., copper, aluminum, etc.) within the via hole and/or atrench to fill the opening, and performing a planarization process(e.g., a chemical mechanical planarization process). In some embodiments(not shown), one or more transistor devices may be formed within thefirst substrate 102 a prior to the formation of the first dielectricstructure 104 a.

As shown in cross-sectional view 1200 of FIG. 12 , a first interconnectwire layer comprising a first interconnect wire 109 w ₁ and a secondinterconnect wire 109 w ₂ is formed within a first ILD layer 414 a on asecond substrate 102 b. In some embodiments, the first ILD layer 414 ais separated from the second substrate 102 b by one or more ILD layers(not shown). In some embodiments, the first interconnect wire layer 108a may be formed by way of a damascene process. In such embodiments, thefirst ILD layer 414 a is formed over the second substrate 102 b. Thefirst ILD layer 414 a is selectively etched to form interconnecttrenches, which are subsequently filled with a conductive material(e.g., tungsten, copper, and/or aluminum). A planarization process(e.g., CMP process) is subsequently performed to remove excess of theconductive material from over the first ILD layer 414 a to define thefirst interconnect wire 109 w ₁ and the second interconnect wire 109 w₂. In some embodiments (not shown), one or more transistor devices maybe formed within the second substrate 102 b prior to the formation ofthe first ILD layer 414 a.

As shown in cross-sectional view 1300 and 1306 of FIGS. 13A and 13B, avia layer comprising a standard via 111 v _(s) and an oversized via 111v _(o) is formed. The standard via 111 v _(s) is formed over the firstinterconnect wire 109 w ₁ and the oversized via 111 v _(o) is formedover the second interconnect wire 109 w ₂. In some embodiments, thestandard via 111 v _(s) and the oversized via 111 v _(o) may be formedby way of a damascene process. In some such embodiments, a second ILDlayer 414 b is formed onto the first ILD layer 414 a, as shown incross-sectional view 1300 of FIG. 13A. The second ILD layer 414 b issubsequently patterned to define a standard via hole 1302 and anoversized via hole 1304. The oversized via hole 1304 has a greater widththan the standard via hole 1302. In some embodiments, the standard viahole 1302 and the oversized via hole 1304 may be formed using a singlephotolithography process (e.g., using a single photomask). The standardvia hole 1302 and the oversized via hole 1304 are then filled with aconductive material (e.g., tungsten, copper, aluminum, and/or the like).

In some embodiments, a chemical mechanical planarization (CMP) processis subsequently performed to remove excess of the conductive materialfrom over the second ILD layer 414 b and to define the standard via 111v _(s) and the oversized via 111 v _(o), as shown in cross-sectionalview 1306 of FIG. 13B. In some embodiments, the CMP process may causeslightly more dishing on the oversized via 111 v _(o) than on thestandard via 111 v _(s). However, it has been appreciated that thedishing of the oversized via 111 v _(o) is small so as to preventshorting or significant leakage within interconnect wires directlyoverlying the oversized via 111 v _(o).

As shown in cross-sectional view 1400 of FIG. 14 , one or moreadditional interconnect layers 1402 are formed onto the standard via 111v _(s) and the oversized via 111 v _(o) to define a second plurality ofinterconnect layers 106 b within a second IC tier 202 b. In someembodiments, the one or more additional interconnect layers 1402 mayhave larger sizes (e.g., widths and/or heights) than the firstinterconnect wire layer and the via layer. In some embodiments, the oneor more additional interconnect layers 1402 may be formed by way of adamascene processes.

As shown in cross-sectional view 1500 of FIG. 15 , the first IC tier 202a is bonded to the second IC tier 202 b by way of a bonding structure204. In some embodiments the first IC tier 202 a may be bonded to thesecond IC tier 202 b by way of a hybrid bonding process. In suchembodiments, a first bonding layer 204 a may be formed onto the first ICtier 202 a and a second bonding layer 204 b may be formed onto thesecond IC tier 202 b. The first bonding layer 204 a and the secondbonding layer 204 b respectively comprise metal bonding regions 206 anddielectric bonding regions 208. The first bonding layer 204 a is broughtinto contact with the second bonding layer 204 b so that the metalbonding regions 206 and the dielectric bonding regions 208 of the firstbonding layer 204 a and the second bonding layer 204 b are aligned.Temperatures of the first bonding layer 204 a and the second bondinglayer 204 b are then increased to form the bonding structure 204. Inalternative embodiments, a direct bonding process, a eutectic bondingprocess, or the like may be used to bond the first IC tier 202 a to thesecond IC tier 202 b.

As shown in cross-sectional view 1600 of FIG. 16 , the second substrate102 b is thinned to reduce a thickness of the second substrate 102 bfrom a first thickness t₁ to a second thickness t₂. In variousembodiments, the second substrate 102 b may be thinned by etching and/ormechanical grinding a back-side of the second substrate 102 b along line1602. In some embodiments, the second substrate 102 b may be thinned bya first grinding process, a subsequent second grinding process, and achemical mechanical polishing (CMP) process.

As shown in cross-sectional view 1700 and 1708 of FIGS. 17A-17B, aback-side of the second substrate 102 b is selectively etched to definea through-substrate via (TSV) opening 1714 extending through the secondsubstrate 102 b to the second interconnect wire 109 w ₂. The TSV opening1714 is defined by sidewalls of the second substrate 102 b. The TSVopening 1714 may also be defined by sidewalls of the second dielectricstructure 104 b.

In some embodiments, the TSV opening 1714 may be formed using twoseparate etching processes. For example, as shown in cross-sectionalview 1700 of FIG. 17A, a first etching process exposes a back-side ofthe second substrate 102 b to a second etchant 1704 according to asecond masking layer 1706 to define an intermediate TSV opening 1702.The intermediate TSV opening 1702 extends through the second substrate102 b to a surface of the second dielectric structure 104 b that isseparated from the second interconnect wire 109 w ₂. A liner 802 isformed along interior surfaces of the intermediate TSV opening 1702. Invarious embodiments, the liner may be formed by way of a depositionprocess (e.g., CVD, PE-CVD, ALD, or the like). As shown incross-sectional view 1708 of FIG. 17B, a second etching process exposesthe liner 802 and the second dielectric structure 104 b to a thirdetchant 1710 according to a third masking layer 1712 to define the TSVopening 1714, which exposes the second interconnect wire 109 w ₂. Insome embodiments, the second etchant 1704 and/or the third etchant 1710may comprise a dry etchant having an etching chemistry comprisingfluorine, chlorine, or the like. In some embodiments, the second maskinglayer 1706 and the third masking layer 1712 may comprise aphotosensitive material (e.g., a photoresist), a hard mask, or the like.

As shown in cross-sectional view 1800 of FIG. 18 , a TSV 112 is formedwithin the TSV opening 1714. In some embodiments, the TSV 112 may beformed by forming one or more conductive materials within the TSVopening 1714. In some embodiments, the liner 802 may separate the one ormore conductive materials from the second substrate 102 b. In variousembodiments, the one or more conductive materials may be formed by wayof a deposition process (e.g., CVD, PE-CVD, ALD, or the like), a platingprocess (e.g., electroplating, electro-less plating, etc.), or the like.In various embodiments, the one or more conductive materials maycomprise tungsten, copper, aluminum, or the like. In some embodiments, aplanarization process (e.g., a CMP process) may be performed afterforming the one or more conductive materials within the TSV opening 1714to remove excess of the one or more conductive materials from along theback-side of the second substrate 102 b.

As shown in cross-sectional view 1900 of FIG. 19 , a bond pad structure114 is formed onto the TSV 112. In some embodiments, the bond padstructure 114 may comprise one or more redistribution layers (RDL)formed onto the TSV 112. In some embodiments, one or more lowerpassivation layers 214-216 may be formed onto the back-side of thesecond substrate 102 b prior to formation of the bond pad structure 114.In some embodiments, the one or more lower passivation layers 214-216may be formed by way of deposition processes (e.g., CVD, PE-CVD, ALD, orthe like). In such embodiments, the one or more lower passivation layers214-216 may be patterned to define a first opening 1902 exposing the TSV112. A conductive material is subsequently formed within the firstopening 1902 and over the one or more lower passivation layers 214-216.The conductive material may be subsequently patterned to define the bondpad structure 114. In some embodiments, the conductive material maycomprise aluminum, tungsten, or the like. In various embodiments, theone or more conductive materials may be formed by way of a depositionprocess, a plating process, or the like.

As shown in cross-sectional view 2000 of FIG. 20 , one or more upperpassivation layers 218-220 are formed over the bond pad structure 114.The one or more upper passivation layers 218-220 may comprise a firstupper passivation layer 218 and a second upper passivation layer 220. Insome embodiments, the one or more upper passivation layers 218-220 maybe formed by way of a deposition process (e.g., CVD, PE-CVD, ALD, or thelike).

The one or more upper passivation layers 218-220 are selectivelypatterned to form a second opening 2002 extending through the one ormore upper passivation layers 218-220. In some embodiments, the secondopening 2002 exposes an upper surface of the bond pad structure 114. Insome embodiments, the one or more upper passivation layers 218-220 maybe selectively patterned by exposing the one or more upper passivationlayers 218-220 to a fourth etchant 2004 according to a fourth maskinglayer 2006. In some embodiments, the fourth etchant 2004 may comprise adry etchant having an etching chemistry comprising fluorine, chlorine,or the like. In some embodiments, the fourth masking layer 2006 maycomprise a photosensitive material (e.g., a photoresist), a hard mask,or the like.

As shown in cross-sectional view 2100 of FIG. 21 , a conductive bondingstructure 118 is formed within the second opening 2002 defined by theone or more upper passivation layers 218-220. In some embodiments, theconductive bonding structure 118 may comprise a UBM 118 a formed ontothe bond pad structure 114 and a conductive bump 118 b (e.g., a solderbump) formed onto the UBM 118 a.

FIG. 22 illustrates a flow diagram of some embodiments of a method 2200of forming an integrated chip structure having an oversized viaconfigured to act as a stop layer for a TSV.

While the methods (e.g., methods 2200 and 3400) disclosed herein isillustrated and described herein as a series of acts or events, it willbe appreciated that the illustrated ordering of such acts or events arenot to be interpreted in a limiting sense. For example, some acts mayoccur in different orders and/or concurrently with other acts or eventsapart from those illustrated and/or described herein. In addition, notall illustrated acts may be required to implement one or more aspects orembodiments of the description herein. Further, one or more of the actsdepicted herein may be carried out in one or more separate acts and/orphases.

At 2202, a first integrated chip (IC) tier is formed to have firstplurality of interconnect layers within a first dielectric structure ona first substrate. FIG. 11 illustrates a cross-sectional view 1100 ofsome embodiments corresponding to act 2202.

At 2204, a first interconnect wire layer comprising a first interconnectwire and a second interconnect wire is formed within a first ILD layeron a second substrate. FIG. 12 illustrates a cross-sectional view 1200of some embodiments corresponding to act 2204.

At 2206, a standard via is formed within a second ILD layer and directlyover the first interconnect wire. FIGS. 13A-13B illustratecross-sectional views, 1300 and 1306, of some embodiments correspondingto act 2206.

At 2208, an oversized via is formed within the second ILD layer anddirectly over the second interconnect wire. FIGS. 13A-13B illustratecross-sectional views, 1300 and 1306, of some embodiments correspondingto act 2208.

At 2210, one or more additional interconnect layers are formed withinadditional ILD layers over the standard via and the oversized via todefine a second IC tier. FIG. 14 illustrates a cross-sectional view 1400of some embodiments corresponding to act 2210.

At 2212, the first IC tier is bonded to the second IC tier by way of abonding structure. FIG. 15 illustrates a cross-sectional view 1500 ofsome embodiments corresponding to act 2212.

At 2214, a thickness of the second substrate is reduced. FIG. 16illustrates a cross-sectional view 1600 of some embodimentscorresponding to act 2214.

At 2216, a backside of second substrate is selectively etched to definea TSV opening extending to the second interconnect wire. FIG. 17illustrates a cross-sectional view 1700 of some embodimentscorresponding to act 2216.

At 2218, a TSV is formed within the TSV opening. FIG. 18 illustrates across-sectional view 1800 of some embodiments corresponding to act 2218.

At 2220, a bond pad structure is formed onto the TSV. FIG. 19illustrates a cross-sectional view 1900 of some embodimentscorresponding to act 2220.

At 2222, one or more upper passivation layers are formed onto the bondpad structure. FIG. 20 illustrates a cross-sectional view 2000 of someembodiments corresponding to act 2222.

At 2224, a conductive bonding structure is formed onto the bond padstructure and within an opening extending through the one or more upperpassivation layers. FIG. 21 illustrates a cross-sectional view 2100 ofsome embodiments corresponding to act 2224.

FIGS. 23-33 illustrate cross-sectional views 2300-3300 of somealternative embodiments of a method of forming an integrated chipstructure having an oversized via configured to act as a stop layer fora TSV. Although FIGS. 23-33 are described in relation to a method, itwill be appreciated that the structures disclosed in FIGS. 23-33 are notlimited to such a method, but instead may stand alone as structuresindependent of the method.

As shown in cross-sectional view 2300 of FIG. 23 , a first integratedchip (IC) tier 202 a is formed. The first IC tier 202 a comprises afirst plurality of interconnect layers 106 a disposed within a firstdielectric structure 104 a on a first substrate 102 a. In someembodiments, the first IC tier 202 a may be formed as described above inrelation to cross-sectional view 1100 of FIG. 11 .

As shown in cross-sectional views 2400 and 2402 of FIGS. 24A-24B, a vialayer having a standard via 111 v _(s) and an oversized via 111 v _(o)is formed within a first ILD layer 414 a. In some embodiments, thestandard via 111 v _(s) and the oversized via 111 v _(o) may be formedusing a damascene process. For example, a first ILD layer 414 a may beformed onto the second substrate 102 b, as shown in cross-sectional view2400 of FIG. 24A. The first ILD layer 414 a is subsequently patterned todefine a standard via hole 1302 and an oversized via hole 1304. Theoversized via hole 1304 has a greater width than the standard via hole1302. As shown in cross-sectional view 2400 of FIG. 24B, a standard via111 v _(s) is formed within the standard via hole 1302 and an oversizedvia 111 v _(o) is formed within the oversized via hole 1304.

As shown in cross-sectional view 2500 of FIG. 25 , a first interconnectwire layer comprising a first interconnect wire 109 w ₁ and a secondinterconnect wire 109 w ₂ is formed over the first ILD layer 414 a. Thefirst interconnect wire 109 w ₁ is formed on the standard via 111 v _(s)and the second interconnect wire 109 w ₂ is formed over the oversizedvia 111 v _(o). In some embodiments, the first interconnect wire 109 w ₁and the second interconnect wire 109 w ₂ may be formed within a secondILD layer 414 b on the first ILD layer 414 a. In other embodiments (notshown), the first interconnect wire 109 w ₁ and the second interconnectwire 109 w ₂ may be formed within the first ILD layer 414 a.

As shown in cross-sectional view 2600 of FIG. 26 , one or moreadditional interconnect layers 1402 are formed onto the firstinterconnect wire 109 w ₁ and the second interconnect wire 109 w ₂ todefine a second IC tier 202 b. In some embodiments, the one or moreadditional interconnect layers 1402 may be formed as described above inrelation to cross-sectional view 1400 of FIG. 14 .

As shown in cross-sectional view 2700 of FIG. 27 , the first IC tier 202a is bonded to the second IC tier 202 b by way of a bonding structure204. In various embodiments, the first IC tier 202 a may be bonded tothe second IC tier 202 b as described above in relation tocross-sectional view 1500 of FIG. 15 .

As shown in cross-sectional view 2800 of FIG. 28 , a thickness of thesecond substrate 102 b is reduced. In various embodiments, the thicknessof second substrate 102 b may be reduced as described above in relationto cross-sectional view 1600 of FIG. 16 .

As shown in cross-sectional view 2900 of FIG. 29 , a back-side of thesecond substrate 102 b is selectively etched to define a TSV opening2902 extending through the second substrate 102 b to the oversized via111 v _(o). In some embodiments, the TSV opening 2902 may be formed asdescribed above in relation to cross-sectional views 1700 and 1708 ofFIGS. 17A-17B.

As shown in cross-sectional view 3000 of FIG. 30 , a TSV 112 is formedwithin the TSV opening 2902. In some embodiments, the TSV 112 may beformed as described above in relation to cross-sectional view 1800 ofFIG. 18 .

As shown in cross-sectional view 3100 of FIG. 31 , a bond pad structure114 is formed onto the TSV 112. In some embodiments, the bond padstructure 114 may be formed as described above in relation tocross-sectional view 1900 of FIG. 19 .

As shown in cross-sectional view 3200 of FIG. 32 , one or more upperpassivation layers 218-220 are formed over the bond pad structure 114.In some embodiments, the one or more upper passivation layers 218-220may be formed as described above in relation to cross-sectional view2000 of FIG. 20 .

As shown in cross-sectional view 3300 of FIG. 33 , a conductive bondingstructure 118 is formed within a second opening 2002 defined by the oneor more upper passivation layers 218-220. In some embodiments, theconductive bonding structure 118 may comprise a UBM 118 a formed ontothe bond pad structure 114 and a conductive bump 118 b (e.g., a solderbump) formed onto the UBM 118 a.

FIG. 34 illustrates a flow diagram of some alternative embodiments of amethod 3400 of forming an integrated chip structure having an oversizedvia configured to act as a stop layer for a TSV.

At 3402, a first integrated chip (IC) tier is formed to have firstplurality of interconnect layers within a first dielectric structure ona first substrate. FIG. 23 illustrates a cross-sectional view 2300 ofsome embodiments corresponding to act 3402.

At 3404, a standard via is formed within a first ILD layer formed on thesecond substrate. FIGS. 24A-24B illustrates cross-sectional views2400-2402 of some embodiments corresponding to act 3404.

At 3406, an oversized via is formed within the first ILD layer. FIGS.24A-24B illustrates cross-sectional views 2400-2402 of some embodimentscorresponding to act 3406.

At 3408, a first interconnect wire layer is formed. The firstinterconnect wire layer comprises a first interconnect wire formed onthe standard via and a second interconnect wire formed on the oversizedvia. FIG. 25B illustrates a cross-sectional view 2500 of someembodiments corresponding to act 3408.

At 3410, one or more additional interconnect layers are formed withinadditional ILD layers over the first interconnect wire layer to define asecond IC tier. FIG. 26 illustrates a cross-sectional view 2600 of someembodiments corresponding to act 3410.

At 3412, the first IC tier is bonded to the second IC tier by way ofbonding structure. FIG. 27 illustrates a cross-sectional view 2700 ofsome embodiments corresponding to act 3412.

At 3414, a thickness of the second substrate is reduced. FIG. 28illustrates a cross-sectional view 2800 of some embodimentscorresponding to act 3414.

At 3416, a back-side of second substrate is selectively etched to definea TSV opening extending to the oversized via. FIG. 29 illustrates across-sectional view 2900 of some embodiments corresponding to act 3416.

At 3418, a TSV is formed within the TSV opening. FIG. 30 illustrates across-sectional view 3000 of some embodiments corresponding to act 3418.

At 3420, a bond pad structure is formed onto the TSV. FIG. 31illustrates a cross-sectional view 3100 of some embodimentscorresponding to act 3420.

At 3422, one or more upper passivation layers are formed onto the bondpad structure. FIG. 32 illustrates a cross-sectional view 3200 of someembodiments corresponding to act 3422.

At 3424, a conductive bonding structure is formed onto the bond padstructure and within an opening in the one or more upper passivationlayers. FIG. 33 illustrates a cross-sectional view 3300 of someembodiments corresponding to act 3424.

Accordingly, in some embodiments, the present disclosure relates to anintegrated chip structure comprising an oversized via that is configuredto act as a stop layer for a through-substrate via (TSV).

In some embodiments, the present disclosure relates to an integratedchip structure. The integrated chip structure includes a standard viadisposed on a first side of a substrate; an oversized via disposed onthe first side of the substrate and laterally separated from thestandard via, the oversized via having a larger width than the standardvia; an interconnect wire vertically contacting the oversized via; and athrough-substrate via (TSV) extending from a second side of thesubstrate, and through the substrate, to physically contact theoversized via or the interconnect wire, the TSV having a minimum widththat is smaller than a width of the oversized via. In some embodiments,the oversized via is vertically between the interconnect wire and thefirst side of the substrate. In some embodiments, the interconnect wireis vertically between the oversized via and the first side of thesubstrate. In some embodiments, the TSV extends vertically through theinterconnect wire and into the oversized via. In some embodiments, theTSV extends vertically through the oversized via and into theinterconnect wire. In some embodiments, the integrated chip structurefurther includes a gate structure disposed on the substrate; a firstinter-level dielectric (ILD) layer laterally surrounding the gatestructure; and a second ILD layer on the first ILD layer, the TSVextending through the first ILD layer to contact the oversized via at aposition that is separated from the second ILD layer by the oversizedvia. In some embodiments, the interconnect wire and the oversized viacollectively have a thickness that is greater than or equal toapproximately 1,000 Angstroms. In some embodiments, the oversized vialaterally extends past opposing sides of the TSV. In some embodiments,the oversized via has a first width that is between approximately 2,000%and approximately 5,000% larger than a second width of the standard via.In some embodiments, the TSV has a rounded surface that physicallycontacts the interconnect wire or the oversized via.

In other embodiments, the present disclosure relates to an integratedchip structure. The integrated chip structure includes a firstintegrated chip tier having a first plurality of interconnect layersdisposed within a first dielectric structure on a first substrate; asecond integrated chip tier having a second plurality of interconnectlayers disposed within a second dielectric structure on a secondsubstrate, the second plurality of interconnect layers including astandard via physically contacting a first interconnect wire, and anoversized via physically contacting a second interconnect wire, theoversized via having a larger size than the standard via; and athrough-substrate via (TSV) extending through the second substrate andphysically contacting the oversized via, the oversized via laterallysurrounding opposing sides of the TSV. In some embodiments, theoversized via has a width that is larger than a width of a surface ofthe TSV that is facing the second interconnect wire. In someembodiments, the integrated chip structure further includes a gatestructure disposed on the second substrate, the TSV vertically extendingfrom between sidewalls of the second substrate to past a surface of thegate structure that faces away from the second substrate. In someembodiments, the integrated chip structure further includes one or moremiddle-end-of-the-line (MEOL) interconnects disposed on the secondsubstrate, the TSV vertically extending from between sidewalls of thesecond substrate to past the one or more MEOL interconnects. In someembodiments, the integrated chip structure further includes a firstinter-level dielectric (ILD) layer on the second substrate; a second ILDlayer on the first ILD layer, the first ILD layer having a higherdielectric constant than the second ILD layer; and the TSV extendingthrough the first ILD layer to contact the oversized via at a positionthat is separated from the second ILD layer by the oversized via. Insome embodiments, the first ILD layer is an oxide or low-k dielectricmaterial and the second ILD layer is an extreme low-k (ELK) dielectricmaterial or an ultra low-k (ULK) dielectric material. In someembodiments, the integrated chip structure further includes a linerdisposed along sidewalls of the TSV and vertically extending through afirst ILD layer of the second dielectric structure, the liner isvertically separated from the oversized via by a non-zero distance.

In yet other embodiments, the present disclosure relates to a method offorming an integrated chip structure. The method includes forming aninterconnect wire within a first inter-level dielectric (ILD) layerformed along a first side of a substrate; forming a standard via withina second ILD layer formed along the first side of the substrate; formingan oversized via within the second ILD layer, wherein the oversized viahas a larger width than the standard via; etching the substrate to forma through-substrate via (TSV) opening extending through the substrate tothe interconnect wire or the oversized via, wherein the interconnectwire contacts the oversized via; and forming one or more conductivematerials within the TSV opening to define a through-substrate via(TSV). In some embodiments, the first ILD layer is between the secondILD layer and the substrate. In some embodiments, the second ILD layeris between the first ILD layer and the substrate.

The foregoing outlines features of several embodiments so that thoseskilled in the art may better understand the aspects of the presentdisclosure. Those skilled in the art should appreciate that they mayreadily use the present disclosure as a basis for designing or modifyingother processes and structures for carrying out the same purposes and/orachieving the same advantages of the embodiments introduced herein.Those skilled in the art should also realize that such equivalentconstructions do not depart from the spirit and scope of the presentdisclosure, and that they may make various changes, substitutions, andalterations herein without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. An integrated chip structure, comprising: a firstvia disposed within a dielectric structure on a substrate; a second viadisposed within the dielectric structure and laterally separated fromthe first via by the dielectric structure, wherein the first via has afirst width that is smaller than a second width of the second via; aninterconnect wire vertically contacting the second via and extendinglaterally past an outermost sidewall of the second via; athrough-substrate via (TSV) arranged over the second via and extendingthrough the substrate, wherein the TSV has a minimum width that issmaller than the second width of the second via; and wherein the secondvia has opposing outermost sidewalls that are laterally outside of theTSV.
 2. The integrated chip structure of claim 1, further comprising: athird via arranged within the dielectric structure, wherein the secondvia is vertically between the third via and the substrate.
 3. Theintegrated chip structure of claim 1, wherein the second via extendsfrom directly below the TSV to laterally past an outermost edge of theTSV.
 4. The integrated chip structure of claim 1, wherein the secondwidth is between approximately 400% and approximately 5,000% larger thanthe first width.
 5. The integrated chip structure of claim 1, whereinthe TSV has angled sidewalls extending through the substrate, the angledsidewalls causing a width of the TSV to get smaller as the TSV getscloser to the second via.
 6. The integrated chip structure of claim 1,wherein the second via has angled sidewalls that cause a width of thesecond via to get smaller as a distance from the substrate decreases. 7.The integrated chip structure of claim 1, further comprising: a secondinterconnect wire contacting the second via, wherein the second via isbetween the interconnect wire and the second interconnect wire.
 8. Theintegrated chip structure of claim 1, further comprising: a plurality ofadditional vias disposed directly below bottoms of both the second viaand the interconnect wire.
 9. The integrated chip structure of claim 1,further comprising: a third via disposed within the dielectricstructure, wherein the first via is vertically between the third via andthe substrate.
 10. The integrated chip structure of claim 1, furthercomprising: one or more transistor devices disposed along a first sideof the substrate, wherein the dielectric structure physically contactsthe first side of the substrate.
 11. The integrated chip structure ofclaim 1, wherein an interior sidewall of the second via is laterallybetween a sidewall of the TSV and a sidewall of the dielectricstructure.
 12. The integrated chip structure of claim 1, wherein thesecond via physically contacts the substrate.
 13. An integrated chipstructure, comprising: a via disposed within a dielectric structure on asubstrate; an interconnect wire vertically contacting the via, whereinthe via is vertically between the interconnect wire and the substrate; athrough-substrate via (TSV) extending through the substrate, wherein theTSV vertically extends through the via and into the interconnect wire;and wherein both the via and the interconnect wire laterally surroundthe TSV (112).
 14. The integrated chip structure of claim 13, furthercomprising: one or more transistor devices disposed along a surface ofthe substrate, wherein the dielectric structure faces the surface of thesubstrate.
 15. The integrated chip structure of claim 13, furthercomprising: a redistribution structure disposed on an opposing side ofthe substrate as the via; and a bonding structure disposed on theredistribution structure, wherein the redistribution structure isbetween the bonding structure and the substrate.
 16. The integrated chipstructure of claim 15, wherein the bonding structure comprises aconductive bump.
 17. An integrated chip structure, comprising: a viadisposed within a dielectric structure on a substrate; an interconnectwire vertically contacting the via, wherein the interconnect wire isvertically between the via and the substrate; a through-substrate via(TSV) extending through the substrate, wherein the TSV verticallyextends through the interconnect wire and into the via; and wherein boththe via and the interconnect wire laterally surround the TSV.
 18. Theintegrated chip structure of claim 17, further comprising: a linerarranged between a sidewall of the TSV and a sidewall of the substrate,wherein the TSV protrudes outward from a bottom of the liner to withinthe dielectric structure.
 19. The integrated chip structure of claim 18,wherein the dielectric structure vertically separates the bottom of theliner from the interconnect wire.
 20. The integrated chip structure ofclaim 18, wherein the dielectric structure comprises an etch stop layerdisposed between adjacent inter-level dielectric (ILD) layers, the linerlaterally separating the TSV from the etch stop layer.